From the Blue Lake, after the last crater, it is nearly all downhill. This shows Lake Rotoiti, from the top of the long slope down the northern edge of the volcano. On a clear day, you really must be able to see for ever!

It is well known that Peter Jackson used parts of Tongariro for the barren environment that Frodo and Sam cross on their way to Mount Doom (modelled by Ngaurahoe, I believe). This crater, one of the smaller ones, shows just how bleak and empty this landscape becomes.

Below the red crater sit the three Emerald Lakes, which are this beautiful colour. As you can see, there are fumaroles on the far side, pushing smoke and sulphur out. Between the wind on the ash and this smoke, it was quite hard on the throat and eyes at times.

The far side of the crater then descends steeply, and the slope is covered in thick ash, along with small fragments of volcanic rock. The easiest way to walk down is to dig your heels in deep at each step; it took me half the slope to get a grip on this technique.
This photo, from the bottom looking up, doesn't really show how steep it is. If you slip (which I did), you just slide a way on your bottom. So long as you stay on the ridge, it's not too bad actually; the ash is lovely and warm after the cold climb. But it creates a small rockslide for the people below which isn't so good.
And there are lots of people! There must have been over 1000 people on the crossing that day, and that's far from unusual. Tourists are bussed in and chucked out into this harsh terrain, and collected the other end. One lass I talked to (a young Swede) didn't even realise she was walking on an active volcano. I was probably one of the slowest walkers that day (a combination of unfitness and a perennial desire to look around, stroke bits of lichen, contemplate the rocks, take pictures and so on.) But I was properly equipped; I saw people in that icy cloud in glittery plimsolls and beach shorts. Not happy people, I have to say.
This track costs a fortune to maintain. Theoretically the bus companies give part of their fee (typically $30) to DOC for this cost, but nothing requires them to do so, or charges the individual tramper. We both think that NZ needs to think of a way of charging tourists, particularly rich world visitors, for their use and abuse of the country's environment.

This is obviously named after the stunning colours of the rock from the minerals coughed up through the huge chimney vent.
The lip of the crater gets very narrow as it climbs a few more meters, to 1886m, the highest point of the crossing. This was probably the most alarming part of the whole walk, because it was very windy at this point. I crouched and waddled the 100m or so in an ungainly way, which felt more stable than a striding walk!

At the top, I ate a sandwich and waited a while. Even so, this was the best I saw of Ngaurohoe, and I never saw Tongariro peak at all! Through the clouds I could see glimpses of the plains below spreading east.
From here there's a flattish plain which narrows as it passes the next crater.

Sarah decided to tackle the Tongariro Alpine Crossing. This is billed as the best one-day hike in NZ, an 18.5km (about 11 mile) walk up one side of Tongariro and down the other. It's said to be challenging, and this day it really was. Starting at 0630, the bus dropped me (and a few others from the campsite, who rapidly left me behind) off at the road end below Ngaurapoe. This is perhaps 1100m high. The first 100 minutes are pretty easy: a gentle climb through low bush developing into alpine bog. Much of the bog has a boardwalk across it, protecting the fragile plants. It was cloudy as we started, cleared for a short while, and then the clouds rolled back up the valley with a vengeance. Ruapehu shrugged off his duvet, rolled one eye at the sun and then pulled it back over his head. I didn't see him again all day.
From Soda Springs the climb begins. A long haul called variously the Devil's or the Giant's Staircase clambers up the first saddle. It is technically a walk, but there's a lot of scrambling involved. For me, it was very, very slow! But I got there in the end.
At the top of the staircase, there's a side track to the top of Ngaurahoe; it was very foggy at this point, and I felt I was getting exercise enough. So I set off across the South Crater. This stretch is as flat as a pancake and as devoid of life as any desert; by now I was high above the treeline, and only lichens were present. Mind you, it was so foggy there could have been forests out there and I wouldn't have known.
On the far side, begins the last bit of climb. This goes up bare rocks, made slippery by the clouds. Gradually the path narrows and narrows; as the cloud got thinner, I could catch glimpses of precipitous drops to both sides. Some parts of the path are slender walkways along the edges of the rocks. There are no ropes to hang on to, and it's not a place for people with vertigo. The wind was icy, cutting through layers of clothing; it seemed most unfair to be smothered with cloud but knifed by wind.
At the top is the signpost for the summit peak of Tongariro, and the pic is proof I made it!

On Friday Sarah took a writing day and Pip went off to the Whakapapa and Whakepapaiti valleys on her own for a six-hour hike. On the way she entered the Hauhungatahi wilderness, with lots of amazing bog life and stunning views of the mountains. She enjoyed it and was glad it was only six hours. Her feet steamed when she put them in water at the other end.
We had two nights in the Discovery Lodge at Tongariro, to have power and do the washing. This place has stunning views, and on Saturday night they had an excellent BBQ on the deck looking across the central plateau at the sunset.

On Thursday, Sarah got the bus south and Pip met her at National Park. (This is the name of the little settlement, which is basically back-packers and ski-lodges.) We drove back up towards Whakapapa, and spent the night at the Mangahuia DOC site (Pip's second night there.) The next day we walked up the river. On the way, we crossed what are known as the Golden Rapids, where the water is stained brown and yellow (gold in the right angle of sunlight) with iron oxide off the mountains.
Climbing above the tree line into alpine bog takes you towards these amazing rapids. The white aluminium-silicate clay is washed down from the peaks, where the silica is created by the heat of the volcanic action. Where the water runs fast, it becomes aerated and the minerals 'fall' out of it to be deposited in these blinding shelves.

The Tongariro Park is named after the northernmost summit of three related volcanoes, Ruapehu, Ngaurahoe and Tongariro. Between Ruapehu and the other two is a high table land, called the Central Plateau. This itself is largely above the tree line, at about 900m plus altitude.
The Maori story has it that a tohunga (priest, shaman) in the great explorations of the North Island, climbed Ruapehu. At the top he was freezing and in great danger. He called out to his sisters in Hai'wiki (the ancestral home of the exploring Polynesians) for the gift of fire. Round the Pacific Rim came the fire, putting subterranean power beneath the mountains. The volcanoes are still very much active.
This is Mt Ngaurahoe (the cone on the right) and Mt Tongariro, taken from the part of the park around Mangahuia, below the village of Whakapapa.